Corrosion inhibited compositions

ABSTRACT

A corrosion inhibited hydrocarbon oil composition comprising a major amount of a mineral oil of lubricating viscosity and a corrosion inhibiting amount of a succinyl derivative selected from the group consisting of N-(carboxylalkylene) hydrocarbyl succinimide characterized by the formula:   N-(carboxylalkylene) hydrocarbyl succinimide acid characterized by the formula:   AND MIXTURES THEREOF WHERE R is alkenyl of from 5 to 20 carbons, R1 is hydrogen or alkyl of from 1 to 10 carbons and n is an integer of from 0 to 5.

nite States Kablaoui et al.

atent [1 1 [4 1 Sept. 2, 1975 CORROSION INHIBITED COMPOSITIONS [75] Inventors: Mahmoud S. Kablaoui, Wappingers Falls; Wheeler C. Crawford, Fishkill, both of NY.

[73] Assignee: Texaco Inc., New York, NY.

[22] Filed: Nov. 5, 1973 [21] Appl. No.: 413,099

[52] U.S. Cl. 252/77; 252/5l.5 A; 252/392 [51] Int. Cl. ClOM 1/32 [58] Field of Search 252/77, 74, 51.5 A, 392

[56] References Cited UNITED STATES PATENTS 3,251,776 5/1966 Gee 252/77 3,796,662 3/1974 Lyle 252/74 3,852,205 12/1974 Koblaoui 252/77 Primary ExaminerMarion E. McCamish Attorney, Agent, or Firm-T. H. Whaley; C. G. Ries; Robert A. Kulason [5 7] ABSTRACT A corrosion inhibited hydrocarbon oil composition comprising a major amount of a mineral oil of lubricating viscosity and a corrosion inhibiting amount of a succinyl derivative selected from the group consisting N-(carboxylalkylene) hydrocarbyl succinimide acid characterized by the formula:

R CH c NH(-CH2) CH-COOH I r n CH2-COOH and mixtures thereof where R is alkenyl of from 5 to 20 carbons, R is hydrogen or alkyl of from 1 to 10 carbons and n is an integer of from 0 to 5.

6 Claims, N0 Drawings 7 l CORROSION INHIBITED COMPOSITIONS BACKGROUND OF INVENTION This invention relates to mineral oil compositions and in particular concerns mineral oil compositions adapted to protect ferrous and other metal surfaces with which they come in contact from rusting and other types of corrosion. One group of metal surfaces particularly prone to corrosion are those metal surfaces found in the transmissions, differentials and hydraulic systems of farm and industrial type tractors. Because of the severe service, the mineral oil compositions utilized in these transmission, differential and hydraulic systems are required to have superior rust protection. Several of the manufacturers of farm and industrial tractors require mineral oil compositions run at least 100 hours in the Humidity Cabinet Rust Test (ASTM D 1748) before failure. Many of the known corrosion inhibited compositions are unable to meet the present day severe antirust requirements such as the aforementioned l hour specification.

Accordingly, it is an object of the present invention to provide a mineral oil composition which will protect metal surfaces with which they come in contact against rusting and corrosion under extreme conditions of service such as found in the present day farm and industrial tractor service.

Another object is to provide improved mineral oil composition containing an effective anticorrosive addi tive which does not adversely affect the other purposes to which the oil may be employed such as a transmission, differential and/or hydraulic fluid.

Other objects wwill be apparent from the following detailed description of the invention and the various advantages not specifically referred to herein will occur to those skilled in the art upon employment of the invention in practice.

SUMMARY OF INVENTION We have discovered and this constitutes our invention a hydrocarbon oil composition of superior corrosion inhibiting properties comprising a major amount of a mineral oil of lubricating viscosity and a corrosion inhibiting amount of a succinyl derivative selected from the group consisting of N-(carboxylalkylene)-alkenyl succinimide characterized by the formula:

R CH c {-CH CH-COOH CH2- c 2 n N-(carboxylalkylene)-alkenyl succinamic acid characterized by the formula:

CHZCOOH and mixtures thereof where R is alkenyl of from 5 to 30 carbons, R is hydrogen or alkyl of from 1 to 10 carbons and n is an integer of from 0 to 5.

DETAILED DESCRIPTION OF THE INVENTION The hydrocarbon oil compositions of the invention comprise between about 0.01 and wt. of the succinyl inhibitor and at least about 50 wt. of a mineral lubricating oil normally having an SUS viscosity at 100F. of between about 120 and 210. The finished compositions of the invention suitable for service use will contain at least about 85 wt. of the mineral oil component and between about 0.01 and 5 wt. of the succinyl inhibitor. The concentrates of the contemplated finished compositions will normally contain between about 50 and 85 wt. of the mineral oil component and between about 5 and 50 wt. of the succinyl inhibitor. Concentrates are formulated for purposes of storage and transport and are converted into the finished composition by dilution of additional amounts of the mineral oil component.

The succinyl inhibitors are prepared in essentially a two stage procedure. In the first stage, an alkene of between about 5 and 30 carbons is contacted with maleic anhydride at a temperature of between about 150 and 300C. utilizing a mole ratio of alkene to maleic anhy dride of between about 1:8 and l:l.2. Under preferred c0nditi0ns,;the reaction is conducted in an inert gas such as nitrogen. At the end of the first stage reaction, the unreacted reactants are normally removed, e.g.. via vacuum distillation leaving as residue hydrocarbyl succinic anhydride intermediate. To the residue there is added an aminocarboxylic acid characterized by the formula: v

COOH

where R and n are as heretofore defined utilizing a mole ratio of hydrocarbyl succinic anhydride to aminocarboxylic acid of about 1:1 at a temperature between about 80 and 200C. normally in the presence of an inert solvent and particularly a solvent which forms azeotropes with Water by-product such as toluene. benzene, heptane, xylene and isooctane. The reaction is normally conducted for a period of between about 1 and 10 hours. Reaction temperatures of between about 80 and 140C. with little or no removal of water byproduct favors the production of the amic acid form of the succinyl compound. Reaction temperatures are between about 80 and 200C. and water removal via an azeotrope favors the production of the imide form of the succinyl compound. Where there is some but incomplete removal of water, both the succinimide and amic forms are found in the reaction mixture. These mixtures of amide and amic are favored from an economic standpoint since the process controls necessary Examples of the hydrocarbon succinic anhydride intermediate contemplated herein are pentenyl succinic anhydride, tetradecenyl succinic anhydride, ndodecenyl succinic anhydride, 3-butyl octenyl succinic anhydride, t-dodecenyl succinic anhydride and octadecenyl succinic anhydride.

Specific examples of the succinyl inhibitors contemplated herein are those of the formulas:

ll I1 R-CH c NCH Q CH-COOH CH2 C CH COOH where R equals t-dodecenyl, R is hydrogen and n is 0; R is hexyl, R is hydrogen and n is 2; and R is 4-propyl octadecenyl, R is decenyl and n is 5.

Typical weight ratios of imide to amic in the mixtures of the succinyl corrosion inhibitor are 4:1, 2:1, 1:1, 1:2 and 1:4.

The mineral lubricating oil base which constitutes at least about 85 wt. of the finished corrosion inhibited composition and at least about 50 wt. of the concentrate thereof is a refined oil or a mixture of refined oils selected according to the viscosity requirements of the particular service. But normally viscosities between about 120 to 210 SUS at 100F. are employed. The base oils are derived from naphthenic, paraffinic or a mixture or naphthenic and paraffinic base oils resulting from petroleum refining. In addition to the succinyl corrosion inhibitors contemplated herein, other additive materials are normally incorporated in the base oil. The particular additive or additives found in said base oils will depend upon the service for which the oil is intended. The additional additives contemplated belong in the classes'of detergent dispersants, VI improvers, extreme pressure agents, antioxidants, antifoamants, antiwear agents, etc.

When detergent-dispersants are employed, they are usually normally utilized in amounts between about 0.5 and 5 wt. 7:. Examples of the ashless dispersant are the alkenyl succinimides characterized by the general formula:

R2 CH C\ 4 CH NH; CH CH N CH NH 2 2 2 CH2 C/ 2 X 2 where R is a monoolefinic aliphatic hydrocarbon radical of from about 50 to 200 carbons and .r is an integer of from 1 to 10 derived from a polyethylene polyamine. Particularly suitable derivatives are the diethylene triamine, triethylene tetramine, tetraethylenepentamine of polyisobutylene succinic anhydride, particularly where R is of a molecular weight between about 700 and 2000, e.g., about 1300. These ashless dispersants are further described in U.S. Pat. Nos. 3,172,892 and 3,202,678. The non ashless dispersants that may be utilized are the alkaline earth metal overbased calcium alkaryl sulfonates such as the carbon dioxide over-based calcium alkyl alkaryl sulfonate wherein the alkaryl sulfonate moiety is of a molecular weight of 500 to 1000. These overbased sulfonates are further described in U.S. Pat. Nos. 3,027,325, 3,312,618 and 3,537,996.

Examples of the extreme pressure agents contemplated herein are dithiolthione derived from sulfurizing triisobutylene and alkyl sulfides, disulfides and polysulfides prepared by sulfurization of isobutylene with sulfur chloride. 7

Examples of contemplated viscosity index improvers are the methacrylate ester polymers characterized by the general formula:

where R is an alkyl group, a dimethylamino group or a mixture of such groups containing from 1 to 20 carbons and y is an integer providing a molecular weight of the polymer in the range of 25,000 to 1,250,000, preferably 35,000 to 200,000. Methacrylate ester polymers possessing pour depressant and viscosity index improving properties are well known, e.g., U.S. Pat. No. 2,737,496. A very effective material of this type is a tetrapolymer in which R represents about 32 wt. lauryl, about 28 wt. butyl, 26 wt. stearyl and 14 wt. hexyl. The methacrylate ester copolymer is employed in the base oil in an amount ranging from about 0.5 to 10 wt. preferably l-5 wt. in order to impart the desired viscosity index and pour point.

Examples of effective antioxidants are the aryl substituted amine antioxidants exemplified by phenylnaph thylamines as well as compounds such as phenylene diamines, phenothiazines, diphenylamines employed in amounts of between about 0.1 and 5 wt. Particularly preferred antioxidants are the phenyl-alphanaphthylamines and a mixture of 2,2-diethyl-4,4-tdioctyl diphenylamine and 2,2'-diethyl-4,6-octyl diphenylamine. These antioxidants can also function as supplementary corrosion inhibitors.

Additional examples of antioxidants are the hydrocarbyl dithiophosphates, particularly effective compounds in this class are the zinc di(nonylphenoxyethyl) dithiophosphate, zinc di(dodecylphenoxyethyl) dithiophosphate and zinc di-(nonlyphenoxyethoxyethyl) dithiophosphate prepared by reacting nonylphenolethylene oxide compounds with phosphorus pentasulfide followed by neutralization of the acid formed with a basic zinc compound such as zinc carbonate, zince oxide or zinc hydroxide. The general preparation and description of the compounds in this class is disclosed in U.S. Pat. Nos. 2,344,395 and 3,293,181.

The following examples further illustrate the invenwhere Z is tion but are not to be construed as limitations thereof.

EXAMPLE 1 This example illustrates the preparation of the succi- 5 nyl corrosion inhibiting component of the compositions CH CH CH3 CH of the invention.

A mixture of l 176 grams (6 moles) of l-tetradecene 2 H H- and 588 grams (6 moles) of maleic anhydride were heated to reflux (197C.) under nitrogen. Heating was 10 continued until the temperature reached 230C. (4 hours). The reaction was then cooled and the starting material was distilled under vacuum 2 mm Hg,

8595C.) about 400 grams was distilled out. To the EXAMPLE residue there was added 332.0 gram e of This example still further illustrates the preparation gly i e (aminoaoetic acid) and 100 of toluonoof the corrosion inhibiting component of the mineral The mixture was then refluxed for 2 hours while azeooil compositions contemplated herein. troping water out. There was collected 54 mls. (3 The procedure of Examplelwas essentially repeated moles) of water via azeotrope. The product was identiwith the exception that 1008 grams of l-decene were fied to be a 2:1 weight mixture of N- employed rather than the l-tetradecene. The final (carboxylmethylene)-n-tetradecenyl succinamic acid product was identified as 2:1 weight mixture of N- and N-(carboxylmethylene)-n-tetradecenyl succini- (carboxylmethylene)-n-decenyl succinamic acid and mide characterized by the formulas: N-(carboxylmethylene)-n-decenyl succinimide.

II II CH -CO0H CH -C 2 2 u Analysis of the mixture found the following: EXAMPLE IV This example illustrates the mineral oil compositions contemplated herein and further demonstrates the su- Tcsts Observed Calcd periority of the contemplated compositions over coma g g parative compositions. The corrosion inhibiting ability I. 2 N 3.6 39 of the representative and comparative compositions Total Acid NtL (TAN) 205 150 for 100% imide were measured in the ASTMD 1748-70 Humidity 300 for 100% amic acid 40 Cabinet Test. Basically, this test comprises dipping steel panels in test oil allowing the excess test oil to drain and then suspend the oil coated test steel panel X M LE E P H in a humidity cabinet at 120F. until the oil fails, the This example further Illustrates the Preparation of greater the number of hours to failure the more effectho succinyl Corrosion inhibiting Component of the tive the corrosion inhibiting properties of the test comeompesltions contemplated herein position A test surface is considered failing when it To 270 grams 1 mole) of t-dodeeenyl sueeinie ycontains one or more dots of rust larger than 1 mm. in dride in 350 mls. of toluene was added 75 grams (1 diameter or if it contains five rust dots of any size. In mOle) of glycine. The reacti n miX r Was h n heated addition, at the end of 120 hours of being subjected to to reflux under nitrogen for a 35 hour period while the humidity cabinet, the test surface is inspected and azeotroping water out. A total of 13.6 mls. of water was an estimate is made of the percent rust covering said collected. This mixture was then filtered and solvent surface. The less hours to failure and/or the greater the stripped to give 320 grams (97% yield) of product idenpercent of rusting of the test panel, the less the corrotified as a mixture of N-(carboxylmethylene)-tsion inhibiting effectiveness of the protective oil comdodecenyl succinamic acid and N-(carboxylmeposition. thylene)-t-dodecenyl succinimide in an amic acid to The representative composition and the comparative imide ratio of about 2:1, the amic acid and imide recompositions and the results of their testing in the huspectively characterized by the formulas: midity cabinet test are found below in Table l.

II II TABLE I RUST INHIBITOR EVALUATION Composition Wt. '71 A B C D Base 99.5 995 99 I Ex. I Prod. 0.5 Ex. II Prod. 0.5 Rust Inhibitor X I H. C. D-I748 I I20 96 24 Hrs. to Failure Rust Several Several Several 20 Spots Spots Spots Base is composed of:

96.7 wt /r Mineral Oil I SUS at l00F.)

3.0 wt. /1 Tetrupolymer of butyl. lauryl.

stearyl and dimcthylaminocthyl mcthucrylalcs 0.3 wt. "/1 Dithiolthionc from triisobutylcnc Rust Inhibitor X:

50 wt. /r l7.5 wt. 7: 5.0 wt. 7! 27.5 wt. "/1

calcium sulfonate tricthoxylatcd nonylphenol hcxylcnc glycol mineral oil As can be seen from the above the representative Compsoitions A and B were substantially more effective in respect to corrosion prevention than a conventional Rust Inhibitor X and superior to the base composition not containing a rust inhibitor, i.e., Composition 0 II R CH C N CHg) CH-COOH CH 0 n N-(carboxyalkylene) hydrocarbyl succinamic acid characterized by the formula:

R CH C NH (-CH CH-COOH v n GH -coon and mixtures thereof where R is alkenyl of from 5 to 30 carbons. R is hydrogen or alkyl or from 1 to 10 carbons and n is an integer of from 0 to 5.

2. A hydrocarbon oil composition in accordance with claim I wherein said succinyl compound is present in an amount of between about 0.01 and 5 wt. and said mineral oil is present in an amount of at least about wt. 7:.

3. A hydrocarbon oil composition in accordance with claim I wherein said mineral oil is present in an amount of at least about 50 wt. and said succinyl derivative is present in an amount of between about 5 and 50 wt. 71..

4. A composition in accordance with claim 1 wherein R is n-tetradecenyl, R is hydrogen and n is 0.

5. A composition in accordance with claim 1 wherein R is t-dodecenyl, R is hydrogen and n is 0.

6. A composition in accordance with claim 1 wherein R is n-decenyl, R is hydrogen and n is 0. 

1. A HYDROCARBON OIL COMPOSITION COMPRISING AT LEAST ABOUT 50 WT. % OF A MINERAL OIL OF LUBRICATING OIL VISCOSITY AND BETWEEN ABOUT 0.01 AND 50 WT. % OF A SUCCINYL DERIVATIVE SELECTED FROM THE GROUP CONSISTING OF N-(CARBOXYALKYLENE) HYDROCARBYL SUCCINIMIDE CHARACTERIZED BY THE FORMULA:
 2. A hydrocarbon oil composition in accordance with claim 1 wherein said succinyl compound is present in an amount of between about 0.01 and 5 wt. % and said mineral oil is present in an amount of at least about 85 wt. %.
 3. A hydrocarbon oil composition in accordance with claim 1 wherein said mineral oil is present in an amount of at least about 50 wt. % and said succinyl derivative is present in an amount of between about 5 and 50 wt. %.
 4. A composition in accordance with claim 1 wherein R is n-tetradecenyl, R1 is hydrogen and n is
 0. 5. A composition in accordance with claim 1 wherein R is t-dodecenyl, R1 is hydrogen and n is
 0. 6. A composition in accordance with claim 1 wherein R is n-decenyl, R1 is hydrogen and n is
 0. 